Here are two ways to update the firmware on Dell iDRAC6 remote access cards.
Both methods require downloading the BIOS from Dell and extracting it from the bundle. For example, this is the 1.70.21 firmware:
Grab this and extract like this:
sh IDRAC6_FRMW_LX_R299265.BIN --extract ./idrac6-1.70.21
The firmware image is now in /tmp/dell/idrac6-1.70.21/payload/firmimg.d6
If you are just updating one machine, then the simplest way to perform the update is to use the Dell bmcfwul tool locally. This is supplied in the dell_ie_nitrogen package, and is installed to /usr/libexec/dell_dup/dell_ie_nitrogen/bmcfwul.
Install the new firmware like this:
If you have several machines to update, the most convenient way to perform the update is with tftp.
First, copy the firmware image to the tftp server, and put it in /tftproot, or wherever the root of your tftp server is located:
scp /tmp/dell/idrac6-1.70.21/payload/firmimg.d6 $ip_of_tftp_server:/tftproot
Then, trigger a firmware upgrade on the machines remotely using either racadm or ssh:
racadm -r host.to.update -u root -p calvin fwupdate -g -u -a $ip_of_tftp_server
ssh host.to.update racadm fwupdate -g -u -a $ip_of_tftp_server